In fanfiction, if Naruto is a jinchuuriki of multiple bijuu, it could mean extreme power levels. He might be able to access a wider range of abilities from different bijuu. For example, he could combine the fire - based attacks of one bijuu with the water - based defenses of another. This would make him an almost unbeatable force in battle scenarios.
Well, it implies that Naruto would have a huge burden and responsibility. Since each bijuu has its own personality and power, Naruto would need to balance and manage them all. He might face internal struggles as the bijuu's wills could conflict. In terms of the story, it would open up a world of possibilities for him to explore new forms of jutsu and power-ups. Maybe he could use the combined strength of all the bijuu to protect the entire ninja world from threats that were previously unbeatable.
His status as the jinchuuriki of all bijuu would change the political landscape of the Naruto universe. Konoha would become the most dominant village. Other villages might seek to either ally with Konoha or try to find ways to counter Naruto's power. It could also lead to a new era of peace as no one would dare to start a war against a being with such overwhelming power. However, there could also be those who would try to take advantage of Naruto's power for their own evil purposes.
Well, you could focus on the relationships between the bijuu themselves in a Naruto multiple bijuu fanfiction. Maybe some of the bijuu have old grudges or alliances that affect how they interact when multiple are involved. Also, consider a plot where a new villain emerges who has the power to corrupt the bijuu. This would force the characters in the fanfiction to find ways to purify the bijuu while also dealing with their combined, but tainted, power. Or, perhaps a time - travel element where a character goes back in time to prevent the separation of the bijuu in the first place, leading to a completely different Naruto world with multiple bijuu in different situations.
Naruto would be an obvious choice. Since he already has a connection with the Nine - Tailed Fox, exploring how he expands that connection to other bijuu could be really interesting. He has the willpower and the heart to handle multiple powerful entities within him.
New relationships could be very interesting. He could become like a big brother to the bijuu spirits. Naruto's kind nature would make him try to understand and protect them. The bijuu might start to see him not just as a host but as a true friend. They could share their stories and experiences with him, and in turn, Naruto could use their knowledge to grow as a ninja and a person. This would be a really unique bond compared to his relationship with just the Nine - Tails.
In this fanfiction, Naruto Jinchuuriki might have god - like powers such as extreme strength. They could potentially have the ability to control nature on a large scale, like summoning massive storms or earthquakes. Their physical endurance might be enhanced to the point where they can withstand attacks that would normally be fatal.
In fanfiction, if Naruto is half - bijuu, it could mean he has enhanced physical abilities. For example, he might have greater strength and speed like a full - bijuu. His chakra reserves could also be much larger, allowing him to perform more powerful jutsu for longer periods.
In many Naruto fanfictions, if Naruto has three bijuu, they could be the Nine - Tails (Kurama) which he already has in the original series, perhaps the Eight - Tails (Gyuki) as it has a connection with Naruto's world and Akatsuki's hunt for the bijuu. And another could be the Three - Tails (Isobu). However, it really depends on the specific plot and creative direction of the fanfiction.